SPECIAL ASPECTS OF THE RELATIONSHIP BETWEEN HUMAN CORPUS CALLOSUM AND FORNIX

Olga Boiagina

Abstract

It is commonly known that the body of the fornix belonging to the limbic brain is fused with the corpus callosum. Therefore, the question arises about the existence of commutation interactions between the limbic brain and the new pallium through the collector system of the corpus callosum, which is probably the mediating link between the subconscious and conscious spheres of a person's mental activity. However, in the literature this question is not discussed in this way.

Aim of research. The aim of this study is to establish whether the fornix has an organic connection with the myeloarchitectonics of the corpus callosum.

Materials and methods. The median whole mounts (about4 mm thick) of the corpus callosum (including the transparent septum and the structures of the fornix) of 10 men aged 36 to 60 years were used in the course of the study. Some of the mounts underwent a complete plastination in epoxy resin. After this they were used to make polished slices, stained with a 1% solution of methylene blue in a 1% borax solution. The remaining mounts of corpus callosum were used to make serial paraffin sections with further hematoxylin and eosin and Van Gieson’s stain.

Results. It has been established that the pillars of the fornix enter the body of the corpus callosum on the border between its trunk and splenium. In the area of contact between the fornix body and the corpus callosum there is a loosened scissura, which gradually narrows toward the splenium and then disappears leading to the complete consolidation of the fornix and corpus callosum. This consolidation is expressed in the fact that the interfunculary connective tissue septa of the latter penetrate into the body of the fornix and as a result it is divided into the cabled-like assemblies of myelinated nerve fibers. However, unlike the corpus callosum, this division is not complete: it concerns only the layer of the fornix that is directly attached to the corpus callosum.

Conclusions. On the boundary between the corpus callosum trunk and its splenium, that is, in the area of its isthmus, the commutation interconnection between the conducting system of the limbic brain and the commissural pathways of the neopallium is structurally fixed